Question 637338
First, let your age be 'x' and let your father's age be 'y'

If your father is 4 times your age, then your father  y = 4x

If the sum of your ages is 70, then x + y = 70

Now we have two equations with two unknowns x and y

Substitute the first equation y = 4x into the second equation x + y = 70.

This means, in the equation x + y = 70, replace y with 4x:


x + 4x = 70

Simplify the left side to get:

5x = 70

Then divide both sides of the equation by 5:

{{{5x/5}}} = {{{70/5}}}

x = 14

Since x + y = 70

We can substitute x = 14 and find y:

14 + y = 70

Subtract 14 from both sides:

14 + y - 14 = 70 - 14

y = 56

Your age is 14 and your dad is 56 years old


You can always check your answer:

Remember the question said, the sum of your ages is 70...

x + y = 70

14 + 56 = 70

You are right!